(Updates prices, adds analyst comments; changes byline, dateline, previous HAMBURG)
CHICAGO, Jan 23 (Reuters) - U.S. grain futures were lower on Tuesday, with wheat down 1 percent and corn heading for its second session of declines on chart-based selling and abundant global stockpiles, traders said.
Soybeans were about unchanged at the Chicago Board of Trade, hovering near roughly six-week highs amid warm and dry conditions that stressed the developing crop in Argentina, the No. 3 soy producer after the United States and Brazil.
There was little fresh news to alter momentum for any of the crops, and investment funds still had sizeable net shorts in each. Rain mixed with snow fell in parts of wheat-growing areas in the U.S. Midwest, providing moisture to the dormant soft red winter wheat crop.
CBOT SRW wheat futures for March delivery were down 4-3/4 cents to $4.21 per bushel while K.C. March hard red winter wheat shed 5-1/4 cents to $4.23-1/4, both the lowest in about a week.
"Everyone is marking time until wheat breaks dormancy," said INTL FCStone analyst Arlan Suderman.
CBOT March corn was down 2-1/4 cents at $3.49-3/4 per bushel at 11:52 a.m. CST (1752 GMT), easing after touching a multi-week high on Monday.
CBOT March soybeans were down 1/2 cent at $9.83-3/4, weakening after an earlier high of $9.88-3/4.
Analytics firm Informa Economics trimmed its forecasts for 2018 U.S. soybean and corn plantings, even as their outlook for 91.387 million soybean acres still would be the most ever.
Argentine soy and corn farmers are facing yield losses this season due to dry, hot weather that persisted over the weekend and was expected to continue in days ahead, a Buenos Aires Grains Exchange weather consultant said on Monday.
Argentina is not in an actual drought but conditions are not optimal for crops, said consultant Eduardo Sierra. (Additional reporting by Michael Hogan in Hamburg and Naveen Thukral in Singapore; Editing by James Dalgleish)